Drinking, Drugs and Driving: Arrest and Tests

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Police officers who suspect a driver of having taken drugs or alcohol can ask the driver to do a breath or physical coordination tests. Here we explain these things:

  • what the police can do with drivers who are not fit to drive
  • tests the police can ask drivers to do to detect alcohol or drugs in their blood 
  • the rights and responsibilities of drivers


Police Can Stop Drivers Who Are Unfit to Drive 

Police officers on patrol and can stop you if you have difficulty controlling your car, for example, you’re not driving straight, can’t stay in your lane, break suddenly for no reason, drive too fast or too slow or get into an accident.  

During random checks, police officers can check your driver’s license and registration papers. At the same time, they can check whether you’re fit to drive. Police can also put up roadblocks and check your blood-alcohol levels and ability to drive.  

You must stop if a uniformed police officer asks you to, no matter the circumstances. The police officer can question you about your car, your driving and whether you had anything to drink. 


Tests When Drivers Are Stopped  

Police officers can stop you if they think you’re in no condition to drive. They can ask you to do screening tests to see if you’ve taken drugs or alcohol. 


Preliminary Breath Test

Police officers who think you’ve been drinking, can order you to give a breath sample using an approved screening device. This device can detect the presence of alcohol in a person’s blood and gives the approximate blood-alcohol level. 

The results of this preliminary test usually can’t be used in court. But they can give a police officer a valid reason to ask you to take a more accurate test at a police station. 


Physical Coordination Tests

Police officers can also ask you to do physical coordination tests if they suspect you’ve taken drugs and are unfit to drive.

For example, they can ask you to walk in a straight line, turn or stand on one foot while counting out loud without losing balance.

They can use the same tests to check whether you’ve had too much to drink. Police officers can also film you while doing physical coordination tests.

In addition, police officers can observe you while talking with you and make notes on anything that shows you’re unfit to drive. Here are examples:

  • strong smell of alcohol on the driver’s breath 
  • red or glassy eyes 
  • slurred or difficult speech 
  • loss of balance for no reason 
  • incoherence, confusion and mood swings 


Drivers’ Rights and Responsibilities 

Police officers must ask you to do the screening tests as soon as possible after stopping you. You have a right to know whether they will arrest you.

If asked by a police officer, you must

  • show you driver’s licence, registration certificate and proof of insurance
  • blow into an approved screening device
  • do physical coordination tests if asked 

Important! Refusing to give a breath sample or do physical coordination tests without good reason is a crime. The punishment is the same as for driving over the legal limit or impaired driving

Police officers can question you but you have the right to remain silent.

Consequences of Failing Initial Screening Tests 

The results of the tests and observations might give police officers reasonable grounds to arrest you for driving over the legal limit or for impaired driving

If arrested, you have the right to speak to a lawyer. 

The police officers may do these things:

  • order you to do more precise tests at a police station 
  • take away your driver’s license for 24 hours 
  • seize your vehicle 

Refusing to go to the police station for further tests is also a crime.

If arrested, you have the right to remain silent but you must give your name, address and other information to confirm your identity. 

For more information, read our article Rights During a Detention or Arrest.  


Tests at a Police Station 

At the police station, you might be asked to do other tests to measure the exact amount of alcohol in your blood or determine whether you’ve taken drugs.


Breath Sample Test 

The breath sample test involves taking a breath sample to measure the level of alcohol in your blood. It is more precise than the preliminary breath test using an approved screening device. If the result shows a blood-alcohol level over the legal limit (.08), it can be used as proof that you committed a crime. A qualified technician, who can be a police officer, gives the test.

Contesting the results of the breath sample test 

The breath test is approved by the government and is usually reliable. But the machine can malfunction and give a wrong result. 

To contest the results of a breath sample test, you must show that the device was not used or did not work properly.  It’s a good idea to consult a lawyer.  


Blood Sample

You can be ordered to give a blood sample if your physical condition at the time of arrest makes it difficult or impossible to give a breath sample.

For example, someone with asthma or a mouth or jaw injury might not be able to blow hard enough in the device to get a reliable breath sample. The police officer can then order the driver to go to the hospital to give a blood sample.


Physical Exam 

Police officers can order more advanced tests done by a qualified officer (evaluating officer) if they think you’ve taken a combination of drugs and alcohol. For example, the evaluating officer can take your pulse or temperature, examine your pupils or ask you to follow an object with your eyes. The evaluating officer can film these tests. Depending on the results, you might be ordered to give a saliva, urine, blood or breath sample

After the tests, you might be formally accused of a crime. If found guilty, you’ll receive a sentence with serious consequences. To learn more, read our article on the consequences of driving under the influence of drugs or alcohol

Important !
This article explains in a general way the law that applies in Quebec. This article is not a legal opinion or legal advice. To find out the specific rules for your situation, consult a lawyer or notary.